Xrepeat
xrepeat and yrepeat are the x and y scale of the sprite, respectively. These are the same values that are set by the sizeat command. Thus:
setactor[THISACTOR].xrepeat 40 setactor[THISACTOR].yrepeat 40
is equivalent to
sizeat 40 40
In the wall struct, xrepeat and yrepeat are the size\stretch of the texture used (if any).
The range of values is 0 to 255, inclusive.